Classically the initial hepatic alteration induced by alcohol is the fatty liver. Recent research has demonstrated that the ethanol-induced fatty liver is a result of ethanol metabolism and not ethanol per se. One theory explaining liver cell injury induced by alcohol metabolism is the mechanism of lipid peroxidation. Since new enzymatic techniques have been developed which allow for the isolation of structurally and functionally intact hepatic parenchymal cells, isolated hepatocytes will be used in an effort to evaluate the role of ethanol and its metabolites--acetaldehyde and acetate--in hepatic lipid peroxidation and triglyceride alterations. Along with measurements of lipid peroxidation and triglycerides, the functional integrity of the isolated cells will also be evaluated in terms of (A) capacity for active transport, (B) response to hormones and (C) levels of ATP and gluconeogenesis. Antioxidants, inhibitors of lipid peroxidation, as well as pyrazole and disulfiram, inhibitors of alcohol metabolism, will be used concomitantly with the hepatocytes in an effort to block alterations induced by ethanol or its metabolites. Since chronic ethanol consumption results in increased ethanol oxidation via various proposed pathways (i.e., MEOS and catalase), hepatocytes isolated from animals chronically exposed to ethanol will also be evaluated. The contribution of the various ethanol oxidation pathways to lipid peroxidation and liver cell injury will be assessed using hepatocytes isolated from animals chronically exposed to ethanol. The composite results of this research proposal will aid in clarifying both the source and role of ethanol-induced lipid peroxidation in liver cell injury.